Organic Compound, Anisotropic Optical Film and Method of Production Thereof

ABSTRACT

The present invention is related to 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives of the general structural formula (I), the anisotropic optical film based on these derivatives with phase-retarding properties for displays, and method of producing thereof: 
     
       
         
         
             
             
         
       
     
     where X is a carboxylic group COOH, m is 0, 1, 2 or 3; Y is a sulfonic group SO 3 H, n is 0, 1, 2 or 3; Z is an acid amide group L-NH 2 ; p is 0, 1, 2 or 3; K is a counterion selected from the list comprising H + , NH 4   + , Na + , K + , Li + , Mg 2+ , Ca 2+ , Zn 2+ , and Al 3+ ; s is the number of counterions providing neutral state of the molecule; R is a substituent selected from the list comprising CH 3 , C 2 H 5 , NO 2 , Cl, Br, F, CF 3 , CN, OH, OCH 3 , OC 2 H 5 , OCOCH 3 , OCN, SCN, NH 2 , and NHCOCH 3 ; w is 0, 1, 2, 3 or 4; and R 1  is a substituent selected from the list comprising H, CH 3 , C 2 H 5 , C 3 H 7 , i-C 3 H 7 , CH 2 CH 2 CH 2 CH 3 , CH(CH 3 )CH 2 CH 3 , CH 2 CH(CH 3 )CH 3  and C(CH 3 ) 3  and L is a linking group.

FIELD OF THE INVENTION

The present invention relates generally to the field of organicchemistry and particularly to organic anisotropic optical films withphase-retarding properties for displays. More specifically, the presentinvention is related to the synthesis of6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives and themanufacture of anisotropic optical films based on these compounds.

BACKGROUND

In connection with polarization, compensation and retardation layers,films, or plates described in the present application, the followingdefinitions of terms are used throughout the text.

The definition of a “thin” optical film is related to the wavelength oflight: a thin optical film is that having a thickness comparable with ahalf of the wavelength of light in the working interval of opticalspectrum.

The term optical axis refers to a direction in which the propagatinglight does not exhibit birefringence. The optical properties of anoptical compensation film are described by the refractive indexellipsoid, with the refractive indices nx, ny, and nz in the directionsof x, y and z axes, respectively. The in-plane x and y axes are mutuallyorthogonal and are both orthogonal to the vertical z axis.

Liquid crystals are widely used in electronics as optical displayelements. In such display systems, a liquid crystal cell is typicallysituated between a pair of polarizer and analyzer plates. The incidentlight is polarized by the polarizer and transmitted through a liquidcrystal cell, where it is affected by the molecular orientation of theliquid crystal that can be controlled by applying a bias voltage acrossthe cell. Then, the thus altered light passes through the second(output) polarizer that is called analyzer. By employing this scheme,the transmission of light from any external source, including ambientlight, can be controlled. The energy required to provide for thiscontrol is generally much lower than that required for controlling theemission from luminescent materials used in other types of displays suchas cathode ray tubes (CRTs). Accordingly, liquid crystal technology isused in a number of electronic imaging devices, including (but notlimited to) digital watches, calculators, portable computers, andelectronic games, for which small weight, low power consumption, andlong working life are important.

The contrast, colour reproduction (colour rendering), and stable greyscale intensity gradation are important quality characteristics ofelectronic displays employing liquid crystal technology. The primaryfactor determining the contrast of a liquid crystal display (LCD) is thepropensity for light to “leak” through liquid crystal elements or cells,which are in the dark or “black” pixel state. In addition, the opticalleakage and, hence, the contrast of an LCD also depend on the directionfrom which the display screen is viewed. Typically, the optimum contrastis observed only within a narrow viewing angle range around the normal(α=0) to the display and falls off rapidly as the polar viewing angle αis increased. The viewing direction herein is defined as a set of thepolar viewing angle (α) and the azimuthal viewing angle (β) as shown inFIG. 1 with respect to a liquid crystal display 1. The polar viewingangle α is measured from the display normal direction 2 and theazimuthal viewing angle β spans between an appropriate referencedirection 3 in the plane of the display surface 4 and the projection 5of viewing arrow 6 onto the display surface 4. Various display imageproperties such as the contrast ratio, color reproduction, and imagebrightness are functions of the angles α and β. In colour displays, theleakage problem not only decreases the contrast but also causes colouror hue shifts with the resulting degradation of colour reproduction.

LCDs are now replacing CRTs as monitors for television (TV) sets,computers (especially in notebook computers and desktop computers),central control units, and various devices, for example, gamblingmachines, electro-optical displays, (e.g., in watches, pocketcalculators, electronic pocket games), portable data banks (such aspersonal digital assistants or mobile telephones). It is expected thatthe proportion of LCD television monitors with a larger screen size willalso sharply increase in the nearest future. However, unless problemsrelated to the effect of viewing angle on the colour reproduction,contrast degradation, and brightness inversion are solved, thereplacement of traditional CRTs by LCDs will be limited.

The type of optical compensation required depends on the type of displayused in each particular system. In a normally black display, the twistednematic cell is placed between polarizers whose transmission axes areparallel to one another and to the orientation of the liquid crystaldirector at the rear surface of the cell (i.e., at the cell side that isaway from the viewer). In the unenergized state (zero applied voltage),normally incident light from the backlight system is polarized by thefirst polarizer and transmitted through the cell with the polarizationdirection rotated by the twist angle of the cell. The twist angle is setto 90 DEG so that the output polarizer (analyzer) blocks this light.Patterns can be written in the display by selectively applying a voltageto the portions of the display that are to appear illuminated.

However, when viewed at large angles, the dark (unenergized) areas of anormally black display will appear bright because of the angle-dependentretardation effect for the light rays passing through the liquid crystallayer at such angles, whereby off-normal incident light exhibits anangle-dependent change in the polarization. The contrast can be restoredby using a compensating element, which has an optical symmetry similarto that of a twist cell but produces the reverse effect. One methodconsists in introducing an active liquid crystal layer containing atwist cell of the reverse helicity. Another method is to use one or moreuniaxial compensators. These compensation methods work because thecompensation element has the same optical symmetry as that of the twistnematic cell: both are made of uniaxial birefringent materials having anextraordinary axis that is orthogonal to the normal light propagationdirection. These approaches to compensation have been widely utilizedbecause of readily available materials with the required opticalsymmetry.

Thus, the technological progress poses the task of developing opticalelements based on new materials with desired controllable properties. Inparticular, important optical elements in modern visual display systemsare optically anisotropic films with optical characteristics optimisedfor use in a particular display module.

Various polymeric materials are known in the prior art, which areintended for use in the production of optically anisotropic films. Filmsbased on these polymers acquire optical anisotropy through uniaxialextension and coloration with organic or inorganic (iodine) dyes.Poly(vinyl alcohol) (PVA) is among polymers that are widely used forthis purpose. However, a relatively low thermal stability of PVA basedfilms limits their applications. PVA based films are described ingreater detail in the monograph Liquid Crystals-Applications and Uses,B. Bahadur (ed.), World Scientific, Singapore-New York (1990), Vol. 1,p. 101.

Organic dichroic dyes constitute a new class of materials currentlygaining prominence in the manufacture of optically anisotropic filmswith desirable optical and working characteristics. Films based on thesematerials can be obtained by applying an aqueous liquid crystal (LC)solution of supramolecules containing dye molecules onto a substratesurface, with the subsequent evaporation of water.

A hydrophobic-hydrophilic balance of molecules of polycyclic organiccompounds makes them soluble in water and stimulates their self-assemblyinto supramolecules. Organic compounds in water form a colloid system orlyotropic liquid crystal, where molecules aggregate into supramoleculesand these supramolecules represent kinetic units of the colloidal system(see, P. I. Lazarev, M. V. Paukshto, “Multilayer optical coating,” U.S.2004/0233528 (2004)). Spectral characteristics and rheologicalproperties of materials (see, V. Nazarov, L. Ignatov, K. Kienskaya,“Electronic Spectra of Aqueous Solutions and Films Made of LiquidCrystal Ink for Thin Film Polarizers,” Molecular Materials, Vol. 14, No.2, pp. 153-163 (2001); S. Remizov, A. Krivoshchepov, V. Nazarov, A.Grodsky, “Rheology of The Lyotropic Liquid Crystalline Material for ThinFilm Polarizers,” Molecular Materials, Vol. 14, No. 2, pp. 179-190(2001)) indicate strong tendency of these molecules to aggregate, evenin diluted aqueous solutions, with formation of supramolecules withcolumnar structure. Columnar structure is specific for flat shapedmolecules grouped in “face-to-face” fashion with hydrophobic molecularplanar cores of aromatic conjugated bond system stacked on each otherinside of the supramolecule core and the hydrophilic peripheral groupsexposed to water. Water provides the medium for electrostaticinteraction and mutual alignment of supramolecules with resultinglyotropic liquid crystal structure of certain symmetry at certain levelof aggregates concentration. Formation of supramolecules starts at lowconcentration of amphiphilic compounds in the water. There are two typesof data that can be used as a basis for previous statement which are (1)optical spectra of molecular compounds that are building block ofsupramolecules, and (2) light scattering data that correlate with sizeof aggregates that are present in the system.

The applied films are rendered anisotropic either by preliminarymechanical orientation of the substrate surface or by post-treatmentusing external mechanical, electromagnetic, or other orienting forcesapplied to the LC film material on the substrate.

Liquid crystal properties of dye solutions are well known. In recentyears, use of liquid crystals based of such dye solutions for commercialapplications such as LCDs and glazing coatings has received muchattention.

Dye supramolecules form lyotropic liquid crystals (LLCs). Substantialmolecular ordering or organization of dye molecules in the form ofcolumns allows such supramolecular LC mesophases to be used forobtaining oriented, strongly dichroic films.

Dye molecules forming supramolecular LC mesophases possess uniqueproperties. These dye molecules contain functional groups located at theperiphery, which render these molecules soluble in water. Organic dyemesophases are characterized by specific structures, phase diagrams,optical properties, and solubility as described in greater detail in: J.Lydon, Chromonics, in Handbook of Liquid Crystals, Wiley VCH, Weinheim(1998), Vol. 2B, p. 981-1007 (see also references therein).

Anisotropic films characterized by high optical anisotropy can be formedfrom LLC systems based on dichroic dyes. Such films exhibit theproperties of so-called E-type polarizers (due to the absorption oflight by supramolecular complexes). Organic conjugated compounds withthe general molecular structure similar to that of dye molecules, butexhibiting no absorption in the visible spectral range, can be used asretarders and compensators.

Retarders and compensators are the films possessing phase-retardingproperties in the spectral regions where the optical absorption isabsent. The phase-retarding or compensating properties of such films aredetermined by their double refraction also known as birefringence (Δn):

Δn=|n _(o) −n _(e)|,

which is the difference of the refractive indices for the extraordinarywave (n_(e)) and the ordinary wave (n_(o)). The n_(e) and n_(o) valuesvary depending on the orientation of molecules in a medium and on thedirection of light propagation. For example, if this direction coincideswith the optical or crystallographic axis, the ordinary polarization ispredominantly observed. If the light propagates in the perpendiculardirection or at some angle to the optical axis, the light emerging fromthe medium will separate into extraordinary and ordinary components.

It is also important to note that, in addition to the unique opticalproperties, the films based on organic aromatic compounds arecharacterized by a high thermal stability and radiation resistance(photostability).

Extensive investigations aimed at the development of new methods forfabricating dye-based films through variation of the film depositionconditions have been described in U.S. Pat. Nos. 5,739,296 and 6,174,394and in published patent application EP 961138. Of particular interest isthe development of new compositions of lyotropic liquid crystals byintroducing modifying, stabilizing, surfactant and/or other additives inthe known compositions, which improve the characteristics of LC films.

There is increasing demand for anisotropic films with improvedselectivity in various wavelength ranges. Films exhibiting differentoptical absorption maxima over a wide spectral interval ranging frominfrared (IR) to ultraviolet (UV) regions are required for a variety oftechnological applications. Hence, much recent research attention hasbeen directed to the synthesis of new materials for the manufacture ofisotropic and/or anisotropic birefringent films, polarizers, retardersor compensators (herein collectively referred to as optical materials orfilms) for LCD and telecommunication applications, such as (but notlimited to) those described in P. Yeh, Optical Waves in Layered Media,New York, John Wiley &Sons (1998) and in P. Yeh and C. Gu, Optics ofLiquid Crystal Displays, New York, John Wiley & Sons, (1999).

It has been found that ultrathin birefringent films can be fabricatedusing the known methods and technologies developed for the production ofoptically anisotropic films based on organic dye LLC systems. Forexample, the manufacture of thin, optically anisotropic crystallinefilms based on disulfoacids of the red dye Vat Red 14 has been describedby P. Lazarev and M. Paukshto, Thin Crystal Film Retarders (in:Proceeding of the 7th International Display Workshops, Materials andComponents, Kobe, Japan, Nov. 29-Dec. 1 (2000), pp. 1159-1160) Inparticular, such films can be obtained using cis- and trans-isomermixtures of naphthalenetetracarboxylic acid dibenzimidazole:

This technology makes it possible to control the direction of thecrystallographic axis of a film during the deposition andcrystallization of LC molecules on a substrate (e.g., on a glass plate).The obtained films have uniform compositions and are characterized byhigh molecular and/or crystal ordering, with a dichroic ratio ofapproximately K_(d)˜28, which makes them useful optical materials, inparticular, for polarizers, retarders, and birefringent films orcompensators.

Thin birefringent films transparent in the visible spectral range havebeen also obtained based on disodium chromoglycate (DSCG):

The anisotropy of oriented films made of DSCG is not very high: adifference in the refractive indices Δn is in the visible range isapproximately 0.1 to 0.13. However, the thicknesses of films based onDSCG can be varied over a wide range, thus making possible thepreparation of films with desired phase-retarding properties despite lowspecific anisotropy characteristics of the material. These films areconsidered in greater detail in T. Fiske et al., Molecular Alignment inCrystal Polarizers and Retarders: Society for Information Display Int.Symp. (Boston, Mass., May 19-24 (2002), Digest of Technical Papers), pp.566-569. The main disadvantage of many of these films is their dynamicinstability, which leads to gradual recrystallization of the LCmolecules and the resulting degradation of the optical anisotropy.

Other anisotropic film materials, based on water-soluble organic dyes,have been also obtained using the aforementioned technology; see, forexample, U.S. Pat. Nos. 5,739,296 and 6,174,394 and European patent EP0961138. However, such materials exhibit high optical absorption in thevisible spectral range, which limits their use in applications requiringtransparent birefringent films.

Still other anisotropic materials have been synthesized based onacenaphtho[1,2-b]quinoxaline sulfoderivatives having the generalstructural formula

where n is an integer in the range from 1 to 4; m is an integer in therange from 0 to 4; z is an integer in the range from 0 to 6; m+z+n≦10; Xand Y are molecular fragments individually selected from the listincluding CH₃, C₂H₅, OCH₃, OC₂H₅, Cl, Br, OH, OCOCH₃, NH₂, NHCOCH₃, NO₂,F, CF₃, CN, OCN, SCN, COOH, and CONH₂; M is a counter ion; and j is thenumber of counter ions in the molecule; with a proviso that, when n=1and SO³⁻ occupies position 1, then m≠0 or z≠0.

Thus, there is a general need for films, which are optically anisotropicand sufficiently transparent in the spectral regions in which they areintended to operate. In particular, there is a need for such opticalfilms transparent in the visible spectral range. It is thereforedesirable to provide improved methods for the synthesis and manufactureof optically anisotropic films. It is also desirable to provide opticalfilms resistant to humidity and temperature variations.

SUMMARY OF THE INVENTION

In a first aspect, the present invention provides a6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative of the generalstructural formula

where X is a carboxylic group —COOH, m is 0, 1, 2 or 3; Y is a sulfonicgroup —SO₃H, n is 0, 1, 2 or 3; Z is an acid amide group -L-NH₂; p is aninteger in the range from 0, 1, 2 or 3; K is a counterion selected fromthe list comprising H⁺, NH₄, Na⁺, K⁺, Li⁺, Mg²⁺, Ca²⁺, Zn²⁺ and Al³⁺; sis the number of counterions providing neutral state of the molecule; Ris a substituent selected from the list comprising —CH₃, —C₂H₅, —NO₂,—Cl, —Br, —F, —CF₃, —CN, —OH, —OCH₃, —OC₂H₅, —OCOCH₃, —OCN, —SCN, —NH₂,and —NHCOCH₃; w is 0, 1, 2, 3 or 4; R₁ is a substituent selected fromthe list comprising —H, —CH₃, —C₂H₅, —C₃H₇, —CH(CH₃)CH₃, —CH₂CH₂CH₂CH₃,—CH(CH₃)CH₂CH₃, —CH₂CH(CH₃)CH₃ and —C(CH₃)₃; and L is a linking group.The values of at least two of said integers m, n and p are not equal to0 and said derivative consequently comprises at least two differentgroups selected from the list comprising X, Y, and Z. Said6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative does notsubstantially absorb incident electromagnetic radiation in the visiblespectral range. In the present invention the visible range is consideredas the wavelength range with a lower boundary of approximately 400 nm,and an upper boundary of approximately 700 nm. It is also supposed thatthe upper boundary of UV spectral range is approximately equal or lowerthat the lower boundary of the visible range.

In a second aspect, the present invention provides an anisotropicoptical film comprising a substrate having front and rear surfaces, andat least one organic layer applied on the front surface of the substrateand comprising at least one6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative with thegeneral structural formula

where X is a carboxylic group —COOH, m is 0, 1, 2 or 3; Y is a sulfonicgroup —SO₃H, n is 0, 1, 2 or 3; Z is an acid amide group -L-NH₂; p is 0,1, 2 or 3; K is a counterion selected from the list comprising H⁺, NH₄⁺, Na⁺, K⁺, Li⁺, Mg²⁺, Ca²⁺, Zn²⁺, Al³⁺ and Ba²⁺, s is the number ofcounterions providing neutral state of the molecule; R is a substituentselected from the list comprising —CH₃, —C₂H₅, —NO₂, —Cl, —Br, —F, —CF₃,—CN, —OH, —OCH₃, —OC₂H₅, —OCOCH₃, —OCN, —SCN, —NH₂, and —NHCOCH₃; w is0, 1, 2, 3 or 4; R₁ is a substituent selected from the list comprising—H, —CH₃, —C₂H₅, —C₃H₇, —CH(CH₃)CH₃, —CH₂CH₂CH₂CH₃, —CH(CH₃)CH₂CH₃,—CH₂CH(CH₃)CH₃ and —C(CH₃)₃; and L is a linking group. The values of atleast two of said integers m, n and p are not equal to 0 and saidderivative comprises at least two different groups selected from thelist comprising X, Y, and Z. Said organic layer does not substantiallyabsorb incident electromagnetic radiation in the visible spectral range.The anisotropic optical film may be an anisotropic optical crystal film.

In a third aspect, the present invention provides a method ofmanufacturing anisotropic optical films comprising the following steps:(a) depositing an aqueous solution of supramolecules, formed from one ormore 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives on asubstrate, and (b) drying said aqueous solution of supramolecules toform a solid layer. Said 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-onederivative has the general structural formula

where X is a carboxylic group —COOH, m is 0, 1, 2 or 3; Y is a sulfonicgroup —SO₃H, n is 0, 1, 2 or 3; Z is an acid amide group -L-NH₂; p is 0,1, 2 or 3; K is a counterion selected from the list comprising H⁺, NH₄,Na⁺, K⁺, Li⁺, Mg²⁺, Ca²⁺, Zn²⁺ and Al³⁺; s is the number of counterionsproviding neutral state of the molecule; R is a substituent selectedfrom the list comprising —CH₃, —C₂H₅, —NO₂, —Cl, —Br, —F, —CF₃, —CN,—OH, —OCH₃, —OC₂H₅, —OCOCH₃, —OCN, —SCN, —NH₂, and —NHCOCH₃; w is 0, 1,2, 3 or 4; R₁ is a substituent selected from the list comprising —H,—CH₃, —C₂H₅, —C₃H₇, —CH(CH₃)CH₃, —CH₂CH₂CH₂CH₃, —CH(CH₃)CH₂CH₃,—CH₂CH(CH₃)CH₃ and —C(CH₃)₃; and L is a linking group. The values of atleast two of said integers m, n and p are not equal to 0 and saidderivative comprises at least two different groups selected from thelist comprising X, Y, and Z. The method of manufacturing an anisotropicoptical film may be a method of manufacturing an anisotropic opticalcrystal film.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a viewing direction defined as a set of the polar viewingangle α and the azimuthal viewing angle (3.

FIG. 2 shows the refractive indices of an organic layer on a glasssubstrate prepared from a mixture of6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylic acid and6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylic acid havingrefractive indices nx=1.631, ny=1.637, and nz=1.844 at a wavelength of550 nm.

FIG. 3 shows the refractive indices of an organic layer on a glasssubstrate prepared from a mixture of2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylicacid and 2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10carboxylic acid having refractive indices nx=1.460, ny=1.840, andnz=1.790 at a wavelength of 550 nm.

FIG. 4 shows a schematic diagram of the cross section of an anisotropicoptical film on a substrate, together with additional adhesive andprotective layers.

FIG. 5 shows a schematic diagram of the cross section of an anisotropicoptical film with an additional antireflection coating.

FIG. 6 shows a schematic diagram of the cross section of an anisotropicoptical film with an additional reflective layer.

FIG. 7 shows a schematic diagram of the cross section of an anisotropicoptical film with a diffuse or specular reflector as the substrate.

DETAILED DESCRIPTION OF THE INVENTION

The general description of the present invention having been made, afurther understanding can be obtained by reference to the specificpreferred embodiments, which are given herein only for the purpose ofillustration and are not intended to limit the scope of the appendedclaims.

In its first aspect, the present invention provides6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives of the generalstructural formula

where X is a carboxylic group —COOH, m is 0, 1, 2 or 3; Y is a sulfonicgroup —SO₃H, n is 0, 1, 2 or 3; Z is an acid amide group -L-NH₂; p is 0,1, 2 or 3; K is a counterion selected from the list comprising H⁺, NH₄⁺, Na⁺, K⁺, Li⁺, Mg²⁺, Ca²⁺, Zn²⁺ and Al³⁺; s is the number ofcounterions providing neutral state of the molecule; R is a substituentselected from the list comprising —CH₃, —C₂H₅, —NO₂, —Cl, —Br, —F, —CF₃,—CN, —OH, —OCH₃, —OC₂H₅, —OCOCH₃, —OCN, —SCN, —NH₂, and —NHCOCH₃; w is0, 1, 2, 3 or 4; R₁ is a substituent selected from the list comprising—H, —CH₃, —C₂H₅, —C₃H₇, —CH(CH₃)CH₃, —CH₂CH₂CH₂CH₃, —CH(CH₃)CH₂CH₃,—CH₂CH(CH₃)CH₃ and —C(CH₃)₃; and L is a linking group. The values of atleast two of said integers m, n and p are not equal to 0 and saidderivative comprises at least two different groups selected from thelist comprising X, Y, and Z. Said6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative does notsubstantially absorb the incident electromagnetic radiation in thevisible spectral range. The number of counterions s may equal zero. Inthis case the molecule is in the neutral state. The counterion may beselected from the group consisting of H⁺, NH₄ ⁺, Na⁺, K⁺, Li⁺, Mg²⁺,Ca²⁺, Zn²⁺ and Al³⁺ or from the group consisting of H⁺, NH₄ ⁺, Na⁺, K⁺,and Li⁺. L is preferably CO or SO₂. In one preferred embodiment of thedisclosed invention, the 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-onederivatives further ensure the absorption of electromagnetic radiationin at least one predetermined wavelength subrange of the UV spectralrange. The molecules of such6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives can absorbelectromagnetic radiation only in a part of the UV spectral range,rather than in the entire range, and this part of the UV range will becalled subrange. This subrange can be determined experimentally for eachparticular 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative. Inone preferred embodiment of the disclosed6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives, at least onesaid acid amide group is carboxyamide CONH₂. In another preferredembodiment of the disclosed6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-ones, at least one said acidamide group is sulfonamide SO₂NH₂. Examples of6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives comprising atleast one carboxylic group COOH, wherein the integer m is between 1 and3 and said derivative has the general structural formula from the groupcomprising structures 1 to 11, are given in Table 1.

TABLE 1 Examples of 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-onederivatives containing carboxylic groups

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

(11)

In another preferred embodiment of the disclosed6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives, said acidgroup, providing solubility in water, is a sulfonic group. Examples ofthe 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives comprisingsulfonic groups SO₃H, wherein integer n is between 1 and 3 and saidderivative has the general structural formula from the list comprisingstructures 12 to 20, are given in Table 2.

TABLE 2 Examples of 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-onederivatives containing sulfonic groups

(12)

(13)

(14)

(15)

(16)

(17)

(18)

(19)

(20)

In one preferred embodiment of the present invention, the derivativecomprises one or more carboxylic acid groups and one or more sulfonicgroups. In another preferred embodiment of the present invention, thederivative comprises one or more carboxylic acid group and one or moresulfonamide groups. In still another preferred embodiment of the presentinvention, the derivative comprises one or more carboxylic acid groupsand one or more carboxyamide groups. In yet another preferred embodimentof the present invention, the derivative comprises one or more sulfonicacid groups and one or more carboxyamide groups. In a possible preferredembodiment of the present invention, the derivative comprises one ormore sulfonic acid groups and one or more sulfonamide groups. In anotherpreferred possible embodiment of the present invention, the derivativecomprises one or more sulfonic acid groups and one or more sulfonamidegroups and one or more carboxyamide groups. In one preferred embodimentof the present invention, the derivative comprises one or morecarboxylic acid groups and one or more sulfonamide groups and one ormore carboxyamide groups. In another preferred embodiment of the presentinvention, the derivative comprises one or more carboxylic acid groupsand one or more sulfonic acid groups and one or more carboxyamidegroups. In still another preferred embodiment of the present invention,the derivative comprises one or more carboxylic acid groups and one ormore sulfonic acid groups and one or more sulfonamide groups. In yetanother preferred embodiment of the present invention, the derivativecomprises one or more carboxylic acid groups and one or more sulfonicacid groups and one or more sulfonamide groups and one or morecarboxyamide groups.

Preferred 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivativesinclude:

-   2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-9-carboxylic    acid;-   2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-10-carboxylic    acid;-   2(3)-sulfonamide-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-9-carboxylic    acid;-   2(3)-sulfonamide-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-10-carboxylic    acid;-   2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-9-carboxylic    acid amide;-   2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-10-carboxylic    acid amide; and-   6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one sulfo-sulfonamides.

In its second aspect, the present invention provides an anisotropicoptical film comprising a substrate having the front and rear surfacesand at least one organic layer applied on the front surface of thesubstrate and comprising at least one6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative with thegeneral structural formula

where X is a carboxylic group —COOH; m is 0, 1, 2 or 3; Y is a sulfonicgroup —SO₃H; n is 0, 1, 2 or 3; Z is an acid amide group -L-NH₂; p is 0,1, 2 or 3; K is a counterion selected from the list comprising H⁺, NH₄,Na⁺, K⁺, Li⁺, Mg²⁺, Ca²⁺, Zn²⁺, Al³⁺ and Ba²⁺, s is the number ofcounterions providing neutral state of the molecule; R is a substituentselected from the list comprising —CH₃, —C₂H₅, —NO₂, —Cl, —Br, —F, —CF₃,—CN, —OH, —OCH₃, —OC₂H₅, —OCOCH₃, —OCN, —SCN, —NH₂, and —NHCOCH₃; w is0, 1, 2, 3 or 4; R₁ is a substituent selected from the list comprising—H, —CH₃, —C₂H₅, —C₃H₇, —CH(CH₃)CH₃, —CH₂CH₂CH₂CH₃, —CH(CH₃)CH₂CH₃,—CH₂CH(CH₃)CH₃ and —C(CH₃)₃; and L is a linking group. The values of atleast two of said integers m, n and p are not equal to 0 and saidderivative comprises at least two different groups selected from thelist comprising X, Y, and Z. Said organic layer does not substantiallyabsorb incident electromagnetic radiation in the visible spectral range.The counterion may be selected from the group consisting of H⁺, NH₄ ⁺,Na⁺, K⁺, Li⁺, Mg²⁺, Ca²⁺, Zn²⁺, Ba²⁺ and Al³⁺ or from the groupconsisting of H⁺, NH₄ ⁺, Na⁺, K⁺, Li⁺, Mg²⁺, Ca²⁺, Zn²⁺, Ba²⁺ and Sr²⁺.In one preferred embodiment of the disclosed anisotropic optical film,said organic layer absorbs electromagnetic radiation in at least onepredetermined spectral subrange of the UV range. Such anisotropicoptical films can absorb electromagnetic radiation only in a part of theUV spectral range, rather than in the entire range, and this part of theUV range is called the subrange. This subrange can be determinedexperimentally for each particular aqueous solution of an6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative used for theformation of the anisotropic optical film. Similarly, the absorptionsubrange can be experimentally determined for a mixture of6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives used for theformation of said film. Thus, such experimentally determined absorptionsubrange electromagnetic radiation can be considered as thepredetermined subrange.

In one embodiment of the disclosed anisotropic optical film, saidorganic layer is substantially insoluble in water and/or inwater-miscible solvents. The6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative used in theanisotropic optical film is preferably as described above with regard tothe first aspect of the present invention. Examples of the6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative comprising atleast one carboxylic group COOH and having the general structuralformula from the group comprising structures 1 to 11 are given in Table1 wherein integer m is between 1 and 3. Examples of the6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives comprising atleast one said sulfonic groups SO₃H and having the general structuralformula from the group comprising structures 12 to 20 are given in Table2 wherein integer n is between 1 and 3. In an embodiment of theanisotropic optical film, said organic layer contains two or more6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives with thegeneral structural formula I, each ensuring the absorption ofelectromagnetic radiation in at least one predetermined wavelengthsubrange of the UV spectral range. In another embodiment of theanisotropic optical film, said6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative formssupramolecules that are oriented predominantly parallel to the substratesurface.

In another preferred embodiment of the anisotropic optical filmaccording to this invention, said organic layer is a biaxial retardationlayer that is characterized by two in-plane refractive indices (nx andny) and one refractive index (nz) in the normal direction. In generalcase the refractive indices (nx, ny and nz) of biaxial retardation layerhave different values.

In one embodiment of the disclosed anisotropic optical film, therefractive indices nx, ny, and nz meet the following condition:nx<ny<nz. In still another preferred embodiment of the anisotropicoptical film, the in-plane refractive indices (nx and ny) and theorganic layer thickness d meet the following condition: d·(ny−nx)<20 nm.In one embodiment of the disclosed anisotropic optical film, thein-plane refractive indices (nx and ny) and the organic layer thicknessd meet the following condition: d·(ny−nx)<10 nm. In still anotherembodiment of the disclosed anisotropic optical film, the in-planerefractive indices (nx and ny) and the organic layer thickness d meetthe following condition: d·(ny−nx)<5 nm.

In another embodiment of the disclosed anisotropic optical film, therefractive indices nx, ny, and nz meet the following condition:nx<nz<ny. In still another preferred embodiment of the anisotropicoptical film, the refractive indices ny and nz and the organic layerthickness d meet the following condition: d·(ny−nz)<20 nm. In oneembodiment of the disclosed anisotropic optical film, the refractiveindices ny and nz and the organic layer thickness d meet the followingcondition: d·(ny−nz)<10 nm. In still another embodiment of the disclosedanisotropic optical film, the refractive indices ny and nz and theorganic layer thickness d meet the following condition: d·(ny−nz)<5 nm.

It is to be noted that conditions nx<nz<ny are equivalent to nx>nz>ny. Arefractive index nx is transformed into a refractive index ny when theCartesian system of coordinates rotates about a vertical axis (0z-axis)by 90 degrees. Similarly a refractive index ny is transformed into arefractive index nx. In this embodiment, the in-plane refractive indicesare not equal among themselves and refractive index in the normaldirection has intermediate value between these in-plane refractiveindices. This ratio of the refractive indexes disclosed in the inventionis invariant relative to a transformation of Cartesian system ofcoordinates.

In one preferred embodiment of the disclosed anisotropic optical film,the substrate is transparent for electromagnetic radiation in thevisible spectral range. In another preferred embodiment of the disclosedanisotropic optical film, said substrate is made of a polymer. In stillanother preferred embodiment of the disclosed anisotropic optical film,the substrate is made of a glass.

In an embodiment of the disclosed anisotropic optical film, thetransmission coefficient of the substrate does not exceed 2% at anywavelength in the UV spectral range. In an embodiment of the disclosedanisotropic optical film, the transmission coefficient of the substratein the visible spectral range is no less than 90%. In another embodimentof the anisotropic optical film, the rear surface of the substrate iscovered with an additional antireflection or antiglare coating. In onepreferred embodiment of the disclosed invention, the substrate furthercomprises a reflective layer that is applied onto the rear surface ofthe substrate.

In a preferred embodiment of the present invention, the anisotropicoptical film further comprises an additional adhesive transparent layerdeposited above said reflective layer. In one embodiment of theanisotropic optical film, the substrate is a specular or diffusivereflector. In another embodiment of the anisotropic optical film, thesubstrate is a reflective polarizer. In still another preferredembodiment, the anisotropic optical film further comprises aplanarization layer deposited onto the front surface of the substrate.In yet another preferred embodiment of the invention, the anisotropicoptical film further comprises an additional transparent adhesive layerplaced on top of the organic layer. In one embodiment of the disclosedinvention, the anisotropic optical film further comprises a protectivecoating formed on the transparent adhesive layer. In one preferredembodiment of the disclosed anisotropic optical film, the transmissioncoefficient of the adhesive layer does not exceed 2% at any wavelengthin the UV spectral range. In another preferred embodiment of thedisclosed anisotropic optical film, the transmission coefficient of theadhesive layer in the visible spectral range is no less than 90%. Instill another preferred embodiment of the disclosed invention, theanisotropic optical film comprises two or more organic layers, whereineach of these layers contains different6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives with thegeneral structural formula I, ensuring the absorption of electromagneticradiation in at least one predetermined wavelength subrange of the UVspectral range.

In its third aspect, the present invention provides a method ofmanufacturing an anisotropic optical film, which comprises the followingsteps: (a) depositing an aqueous solution of supramolecules, formed fromone or more 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives ona substrate, and (b) drying of said aqueous solution of supramoleculesto form a solid layer, wherein said6,7-dihydrobenzimidazo[1,2-quinazolin-6-one derivative has the generalstructural formula

Here, X is a carboxylic group —COOH; m is 0, 1, 2 or 3; Y is a sulfonicgroup —SO₃H; n is 0, 1, 2 or 3; Z is an acid amide group -L-NH₂; p is 0,1, 2 or 3; K is a counterion selected from the list comprising H⁺, NH₄⁺, Na⁺, K⁺, Li⁺, Mg²⁺, Ca²⁺, Zn²⁺ and Al³⁺; s is the number ofcounterions providing neutral state of the molecule; R is a substituentselected from the list comprising —CH₃, —C₂H₅, —NO₂, —Cl, —Br, —F, —CF₃,—CN, —OH, —OCH₃, —OC₂H₅, —OCOCH₃, —OCN, —SCN, —NH₂, and —NHCOCH₃; w is0, 1, 2, 3 or 4; R₁ is a substituent selected from the list comprising—H, —CH₃, —C₂H₅, —C₃H₇, —CH(CH₃)CH₃, —CH₂CH₂CH₂CH₃, —CH(CH₃)CH₂CH₃,—CH₂CH(CH₃)CH₃ and —C(CH₃)₃; and L is a linking group. The values of atleast two of said integers m, n and p are not equal to 0 and saidderivative comprises at least two different groups selected from thelist comprising X, Y, and Z. The counterion may be selected from thegroup consisting of H⁺, NH₄ ⁺, Na⁺, K⁺, Li⁺, Mg²⁺, Ca²⁺, Zn²⁺, and Al³⁺or from the group consisting of H⁺, NH₄ ⁺, Na⁺, K⁺ and Li⁺.

In another preferred embodiment of the invention, the method furtherincludes the application of an external alignment action upon theaqueous solution of supramolecules prior to the drying step.

In still another preferred embodiment of the disclosed method, saidaqueous solution also ensures the absorption of electromagneticradiation in at least one predetermined wavelength subrange of the UVspectral range. Such aqueous solutions absorb electromagnetic radiationonly in a part of the UV spectral range, rather than in the entirerange, and this part of the UV range is called the subrange. Thissubrange can be determined experimentally for each particular aqueoussolution of an 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivativeused for the formation of the anisotropic optical film. Similarly, theabsorption subrange can be experimentally determined for a mixture of6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives used for theformation of said film. Thus, such experimentally determined absorptionsubrange electromagnetic radiation can be considered as thepredetermined subrange.

The 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative used in themethod of the present invention is preferably as described above withregard to the first aspect of the present invention.

In one embodiment, the acid group, providing solubility in water, is acarboxylic group. Examples of the6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives comprising atleast one carboxylic group —COOH and having the general structuralformula from the group comprising structures 1 to 11 are given in Table1, wherein integer m is between 1 and 3. In another embodiment, the acidgroup, providing solubility in water, is a sulfonic group. Examples ofthe 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives comprisingat least one sulfonic group —SO₃H and having the general structuralformula from the group comprising structures 12 to 20 are given in Table2 wherein said integer n is between 1 and 3.

In one preferred embodiment of the disclosed method, said aqueoussolution is based on a water-miscible solvent. In still anotherpreferred embodiment of the disclosed method, the drying step comprisestreatment with an airflow. In yet another preferred embodiment of thedisclosed method, the drying step is performed with or without anairflow at an elevated temperature of 23 to 60 degrees centigrade. Thistemperature range reduces recrystallization and exfoliation (orcracking) of the solid layer. In an embodiment of the disclosed method,the substrate is pretreated so as to provide surface hydrophilizationbefore application of said aqueous solution. In another embodiment ofthe present invention, the disclosed method further includes treatmentof the formed solid layer having the sulfonic groups with a solution ofa water-soluble inorganic salt with a Ba²⁺ cation. In one embodiment ofthe disclosed method, an aqueous solution of supramolecules has aconcentration selected from the range between 1% and 35% to produce thefilm having the predetermined properties. In one embodiment of thedisclosed method, the application of said6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative solution ontothe substrate is accompanied or followed by an external orienting actionupon this solution. In yet another preferred embodiment of the disclosedmethod, the cycle including the technological operations of solutionapplication, alignment action, and drying is repeated two or more times,and sequential solid layers are formed using either the same ofdifferent aqueous solutions, which absorb electromagnetic radiation inat least one preset spectral subrange of the UV spectral range.

In one embodiment of the present invention the aqueous solution ofsupramolecules is a lyotropic liquid crystal solution. In anotherembodiment of the present invention the aqueous solution ofsupramolecules is a gel-like solution.

Other objects and advantages of the present invention will becomeapparent upon reading detailed description of the examples and theappended claims provided below, and upon reference to the drawings.

In order that the invention may be more readily understood, reference ismade to the following examples, which are intended to be illustrative ofthe invention, but are not intended to be limiting in scope. All theabovementioned compounds can be produced by the known ways (sulfonation,sulfochlorination and amidation) from6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one and its carboxylic acids.Besides they can be synthesized by the direct condensation of isatin ando-phenylenediamine substituted with appropriate substituents.

EXAMPLES Example 1

This example describes the synthesis of a mixture of2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylicacid and2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylicacid

The first stage is the synthesis of the mixture of6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylic acid and6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylic acid.[0068]3,4-Diaminobenzoic acid (5.0 g) is dissolved in the mixture ofwater and hydrochloric acid (84.0 g of water and 3.4 g of 35%-solutionof HCl) at 20° C. Isatin (4.8 g) is mixed with 70.0 g of glacial aceticacid and 30.0 g of water. The solution of 3,4-diaminobenzoic acid isadded to the suspension of isatin and the resulting mixture is stirredfor 5 min. Then peroxyacetic acid (6.4 g of 39%) is added. The reactiontemperature is raised to 50° C. and the reactive mass is kept at thistemperature for 20 min, whereupon the temperature is reduced to ambienttemperature. Resulting suspension is filtered, the filter cake is washedwith diluted acetic acid (50 ml of acetic acid in 100 ml of water). Theprecipitate is air dried for 15 hours at 100° C. The process yielded 6.6g of the mixture of6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylic acid and6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylic acid.

The mass spectrum of the product recorded using a Vision 2000spectrometer is as follows: m/z, 279.3; mol. wt., 279.06. ¹H NMR (BrukerWM-250, DMSO-d₆, δ ppm): 7.39 (q, 2H, 8 Hz); 7.68 (t, 1H, 6 Hz); 7.88(d, 2H); 8.09 (d, 1H); 8.32 (d, 1H); 8.95 (s, 1H); (isomers mixture).The electronic absorption spectrum of an aqueous solution of the productmeasured using an Ocean PC 2000 UV/VIS spectrophotometer showed theabsorption maxima at λ_(max1)=325 nm and λ_(max2)=335-340 nm. Theelemental analyses gave the following results (%): C, 64. 52; H, 3. 25;N, 15.05; (anal. calcd. for C₁₅H₉N₃O₃); C, 64. 71; H, 3. 13; N, 15.00(found).

Finally, this example describes the synthesis of the mixture of2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylicacid and 2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10carboxylic acid. A mixture of sulfo-carboxylic acids of6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one is synthesized bysulfonation of the mixture of 9- and 10-carboxylic acids of6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one. Mixture of 9- and10-carboxylic acids of 6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one(5.0 g) is added to 50 ml of 20% oleum and stirred for 1 h at roomtemperature. The reaction mass is diluted with water (85 ml). Theevolved precipitate is filtered and washed with diluted HCl by slurrying(150 ml of 1% HCl×4) and filtered. The precipitate is air dried at 120°C. The process yielded 4.0 g of the mixture of2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylicacid and2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylicacid.

The mass spectrum of the product recorded using a Vision 2000spectrometer is as follows: m/z, 359.4; mol. wt., 359.02. The electronicabsorption spectrum of an aqueous solution of the product measured usingan Ocean PC 2000 UV/VIS spectrophotometer showed the absorption maximaat λ_(max1)=325 nm and λ_(max2)=335-340 nm. The elemental analyses gavethe following results (%): C, 50.14; H, 2.52; N, 11.69; S, 8.92; (anal.calcd. for C₁₅H₉N₃O₆S); C, 50.44; H, 2.54; N, 11.87 (found).

Example 2

This example describes the synthesis of a mixture ofsulfonamide-carboxylic acids of6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one, which is performedaccording to the following scheme:

A mixture of 6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylicacid and 6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylicacid (5.0 g) is stirred with chlorosulfonic acid (50 ml) at 95° C. for 4hour. Then, the reaction mass is poured into ice (150 g). Theprecipitate is separated by filtration and washed with ice-cold water(100 ml) until neutral reaction of the wash water. According to HPLCdata, the residue on the filter contained 91.5% of the target productand 5% of a carboxysulfonic acid derivative.

This residue is introduced by small portions into aqueous ammoniasolution (50 ml), and the mixture is stirred for about one hour at roomtemperature. Then, the ammonia solution is acidified to pH 2.5 by addingsulfuric acid. The precipitate is filtered, suspended in 3% hydrochloricacid (100 ml), and filtered again. The residue is washed with water (60ml). This procedure yielded 3.9 g of2(3)-sulfonamide-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylicacid and2(3)-sulfonamide-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylicacid mixture (the product comprises 87% of the target compound and 5% ofa carboxysulfonic acid derivative). The precipitate is air dried at 105°C.

The mass spectrum of the product recorded using a Vision 2000spectrometer is as follows: m/z, 358.6; mol. wt., 358.04. The electronicabsorption spectrum of an aqueous solution of the product measured usingan Ocean PC 2000 UV/VIS spectrophotometer showed the absorption maximaat λ_(max1)=325 nm and λ_(max2)=335-340 nm. The elemental analyses gavethe following results (%): C, 50.28; H, 2.81; N, 15.64; S, 8.95 (anal.calcd. for C₁₅H₁₀N₄O₅S); C, 50.63; H, 2.88; N, 16.01 (found).

Example 3

This example describes the synthesis of a mixture of2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylicacid amide and2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylicacid amide.

At first, this example describes the synthesis of a mixture of6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylic acid amideand 6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylic acidamide, which is performed according to the following scheme:

A mixture of 9-carboxy-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one (6g) with thionyl chloride (60 ml) is boiled for 2.5 hours. The finalreaction mixture is filtered, and the residue is washed with carbontetrachloride (50 ml). After vacuum drying, the precipitate is graduallyintroduced into aqueous ammonia solution (90 ml) with cooling onice-cold water bath, so that the temperature of the reaction mixture iskept around 5° C. The obtained suspension is stirred for 30 min at theindicated temperature and then heated to 45° C. and stirred at thistemperature for 30 min. The precipitate is filtered hot and washed withwater (130 ml). The precipitate is air dried at 105° C. This procedureyielded 4.3 g of mixture of6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylic acid amideand 6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylic acidamide (the target compound content according to HPLC is 96.0%).

The mass spectrum of the product recorded using a Vision 2000spectrometer is as follows: m/z, 278.2; mol. wt., 278.08. The electronicabsorption spectrum of an aqueous solution of the product measured usingan Ocean PC 2000 UV/VIS spectrophotometer showed the absorption maximaat λ_(max1)=245-250 nm and λ_(max2)=335-340 nm. The elemental analysesgave the following results (%): C, 64.74; H, 3.62; N, 20.13; (anal.calcd. for C₁₅H₁₀N₄O₂); C, 64.53; H, 3.86; N, 20.01 (found).

Finally, this example describes the synthesis of a mixture of2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylicacid amide and2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylicacid amide.

A mixture of 6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylicacid amide and6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylic acid amide(4.0 g) is stirred with 20% oleum (40 ml) for 1 hour at roomtemperature. The reaction mass is diluted with water (68 ml) and theprecipitate is separated by filtration and washed twice at slurryingwith 3% hydrochloric acid (150 ml×2). The precipitate is air dried at100° C. The procedure yielded 4.2 g of mixture of2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylicacid amide and2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylicacid amide.

The mass spectrum of the product recorded using a Vision 2000 UV/VISspectrometer (negative ion reflection mode) is as follows: m/z, 358.6;mol. wt., 358.04. The electronic absorption spectrum of an aqueoussolution of the product measured using an Ocean PC 2000 UV/VISspectrophotometer showed the absorption maxima at λ_(max1)=325 nm andλ_(max2)=335-340 nm. The elemental analyses gave the following results(%): C, 50.28; H, 2.81; N, 15.64; (anal. calcd. for C₁₅H₁₀N₄O₅S); C,49.94; H, 2.93; N, 16.00 (found).

Example 4

This example describes the synthesis of a mixture ofsulfonamide-sulfonic acids of6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one, which is performedaccording to the following scheme:

The first stage is the synthesis of a mixture of sulfonamide-sulfonicacids of 6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one. To this end, amixture of 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one (3 g) andchlorosulfonic acid (18 ml) is stirred for 2 hours at 45-50° C. Thereaction mass is poured into ice (100 g). The precipitate is separatedby filtration and washed on the filter with ice-cold water (100 ml)until neutral reaction of the wash water. This precipitate is introducedinto aqueous ammonia solution (60 ml) and stirred for 30 min at roomtemperature and then for 30 min at 40° C. Then, the solution is filteredfrom insoluble contaminations and acidified to pH 6.7 with hydrochloricacid. The precipitate is separated by filtration and washed with water(120 ml). The yield of the intermediate sulfonamide mixture is 2.1 g.

Sulfonation of the obtained mixture of6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one sulfonamides is carriedout as follows. 6,7-Dihydrobenzimidazo[1,2-c]quinazolin-6-onesulfonamides (2 g) were introduced into 20% oleum (12 ml) and themixture is stirred for one hour at room temperature. The reaction massis diluted with water (22 ml). The precipitate is filtered and washedtwice at slurrying with diluted HCl (30 ml of 3% HCl). Finally, theproduct is dried in vacuum. This procedure yielded 2 g of the mixture of6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one sulfo-sulfonamides.

The mass spectrum of the product recorded using a Vision 2000spectrometer is as follows: m/z, 394.4; mol. wt., 394.00. The electronicabsorption spectrum of an aqueous solution of the product measured usingan Ocean PC 2000 UV/VIS spectrophotometer showed the absorption maximaat λ_(max1)=325 nm and λ_(max2)=335-340 nm. The elemental analyses gavethe following results (%): C, 42.64; H, 2.56; N, 14.21; (anal. calcd.for C₁₄H₁₀N₄O₆S₂); C, 42.45; H, 2.93; N, 14.44 (found).

Example 5

This example describes the preparation of an organic layer from alyotropic liquid crystal solution. A mixture of6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylic acid and6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10-carboxylic acid (2g)obtained as described in Example 1 is further stirred for 1 hour at atemperature of 20° C. in a mixture of 9.0 ml of deionised water with 2.0ml of a 10% aqueous ammonia solution until a lyotropic liquid crystalsolution is formed. At temperature of 20° C. and relative humidity of65% the obtained solution is applied onto a pretreated glass platesurface with a Mayer rod #2.5 moved at a linear velocity of 15 mm/s anddries. In order to determine the optical characteristics of the organiclayer, the optical transmission spectrum was measured in a wavelengthrange from 400 to 700 nm using a Cary 500 spectrophotometer. The opticaltransmission of the organic layer is measured using the light beamslinearly polarized parallel and perpendicular to the coating direction(T_(par) and T_(per), respectively). The obtained data were used tocalculate the refractive indices (nx, ny, and nz) presented in FIG. 2.The obtained organic layer has refractive indices nx=1.631, ny=1.637,and nz=1.844 at 550 nm wavelength. The measurements showed essentiallysmall values of the absorption coefficients of the organic layer.

Example 6

This example describes the preparation of an organic layer from alyotropic liquid crystal solution. A mixture of2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-9-carboxylicacid and 2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one-10carboxylic acid (2g) obtained as described in Example 1 is stirred for 1hour at a temperature of 20° C. in a mixture of 9.0 ml of deionisedwater with 2.0 ml of a 10% aqueous ammonia solution until a lyotropicliquid crystal solution is formed. At temperature of 20° C. and relativehumidity of 65% the obtained solution is applied onto a pre-treatedglass plate surface with a Mayer rod #2.5 moved at a linear velocity of15 mm/s and is dried after that. In order to determine the opticalcharacteristics of the organic layer, the optical transmission spectrumis measured in a wavelength range from 400 to 700 nm using a Cary 500spectrophotometer. The optical transmission of the organic layer ismeasured using the light beams linearly polarized parallel andperpendicular to the coating direction—T_(par) and T_(per),respectively. The obtained data were used to calculate the refractiveindices (nx, ny, and nz) presented in FIG. 3. The obtained organic layerhas refractive indices nx=1.460, ny=1.840, and nz=1.790 at 550 nmwavelength. The measurements showed essentially small values of theabsorption coefficients of the organic layer.

Example 7

FIG. 4 shows the cross section of anisotropic an optical film formed onsubstrate 7. The film comprises organic layer 8, adhesive layer 9, andprotective layer 10. Substrate 7 is made of poly(ethylene terephthalate)(PET) (e.g., Toray QT34/QT10/QT40, or Hostaphan 4607, or Dupont TeijinFilm MT582). The substrate has a thickness from 30 to 120 μm and arefractive index of n=1.5 (Toray QT10), 1.7 (Hostaphan 4607), 1.51(Dupont Teijin Film MT582). The organic layer can be manufactured usingthe methods described in Example 6. The polymer layer 10 protects theanisotropic optical film from damage in the course of itstransportation. This anisotropic optical film is a semiproduct, whichcan be used as an external retarder, for example, in LCDs. Upon theremoval of protective layer 10, the remaining film is applied onto anLCD glass with adhesive layer 9.

Example 8

An anisotropic optical film with an organic layer 11 (FIG. 5) andotherwise identical to the film described above can be applied to theLCD front surface. For example, an antireflection layer of silicondioxide (SiO₂) reduces by 30% the fraction of light reflected from theLCD front surface.

Example 9

With the above described anisotropic optical film applied to the frontsurface of an electrooptical device or an LCD, an additional reflectivelayer 12 can be formed on the rear substrate surface (FIG. 6). Thereflective layer can be obtained, for example, by depositing analuminium film.

Example 10

FIG. 7 shows the organic layer 8 is applied onto the diffuse or specularsemitransparent reflector 12 that serves as a substrate (FIG. 7). Thereflector layer 12 may be also covered with planarization layer 13(optional), which can be made of polyurethane, an acrylic polymer, orany other material. The substrate 12 can be made of PET (e.g., TorayQT34/QT10/QT40, Hostaphan 4607, or Dupont Teijin Film MT582). Thesubstrate thickness is 30 to 120 μm and a refractive index is n=1.5(Toray QT10), 1.7 (Hostaphan 4607), 1.51 (Dupont Teijin Film MT582). Theorganic layer can be manufactured using the method described in Example6. The adhesive layer 9 and the protective layer 10 are applied on topof the organic layer.

Example 11

This example describes the preparation of an organic layer from agel-like aqueous solution of supramolecules. A mixture of sulfo-carboxyderivative of 6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one (1.3 g)obtained as described in Example 1 is stirred for 1 hour at temperatureof 40° C. in a mixture of 22.0 ml of deionised water with 1.0 g ofanhydrous Zinc oxide plus 2.0 ml of a 10% aqueous sodium hydroxide untila clear solution is formed. The pH of obtained solution (Solution 1) isadjusted by additional amount of 1% aqueous Sodium hydroxide solution.pH level of Solution 1 is set to pH=4.96 value and let sit overnight.After approximately 20 hours, Solution 1 is set to pH level 7.0 byadding a few drops of 1% aqueous Sodium hydroxide solution withsimultaneous mixing with use of a magnetic stirrer with a pH-meterelectrode immersed into liquid. The obtained solution (Solution 2) isconcentrated on a rotary evaporator until concentration of sulfo-carboxyderivative of 6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one equal to 7%(w/w %) is reached. At temperature of 20° C. and a relative humidity of65% the obtained solution (Solution 3) is applied onto a pretreatedglass plate surface with a Mayer rod #4 moved at a linear velocity of 10mm/s, and then is dried in an airflow. In order to determine the opticalcharacteristics of the organic layer, the optical transmission spectrumis measured in a wavelength range from 400 to 700 nm using a Cary 500spectrophotometer. The optical transmission of the organic layer ismeasured using the light beams linearly polarized parallel andperpendicular to the coating direction—T_(par) and T_(per),respectively. The obtained data were used to calculate the refractiveindices (nx, ny, and nz). The obtained organic layer has refractiveindices nx=1.495, ny=1.839, and nz=1.841 at a wavelength of 550 nm. Themeasurements showed essentially small values of the absorptioncoefficients of the organic layer.

Example 12

This example describes the preparation an organic layer from a gel-likeaqueous solution of supramolecules. A mixture of sulfo-carboxyderivative of 6,7-dihydrobenzimidazo[1,2-c]quinazoline-6-one (1 g)obtained as described in Example 1 is stirred for 1 hour at temperatureof 40° C. in a mixture of 39.0 ml of deionised water with 0.3 g ofanhydrous Aluminium chloride plus 2.0 ml of a 10% aqueous sodiumhydroxide until a clear solution is formed. The pH of the obtainedsolution (Solution 1) is controlled by an additional amount of 1% waterSodium hydroxide solution. After 1 hour of mixing, Solution 1 is set topH level 6.54 by means of adding few drops of 1% aqueous Sodiumhydroxide solution while mixed on a magnetic stirrer with a pH-meterelectrode immersed into liquid. At temperature of 20° C. and relativehumidity of 65% the obtained solution (Solution 2) is applied onto apretreated glass plate surface with a Mayer rod #4 moved at a linearvelocity of 10 mm/s, and is then dried in an airflow. In order todetermine the optical characteristics of the organic layer, the opticaltransmission spectrum is measured in a wavelength range from 400 to 700nm using a Cary 500 spectrophotometer. The optical transmission of theorganic layer is measured using the light beams linearly polarizedparallel and perpendicular to the coating direction—T_(par) and T_(per),respectively. The obtained data were used to calculate the refractiveindices (nx, ny, and nz). The obtained organic layer has refractiveindices nx=1.495, ny=1.655, and nz=1.660 at a wavelength of 550 nm. Themeasurements showed essentially small values of the absorptioncoefficients of the organic layer.

1-20. (canceled)
 21. A composition comprising a6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative of structuralformula I or a salt thereof:

wherein said derivative does not substantially absorb incidentelectromagnetic radiation in the visible spectral range.
 22. Thecomposition of claim 21, wherein the composition comprises:2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-9-carboxylicacid, or a salt thereof;2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-10-carboxylicacid, or a salt thereof; or a mixture of2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-9-carboxylicacid, or a salt thereof, and2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-10-carboxylicacid, or a salt thereof.
 23. An anisotropic optical film comprising atleast one organic layer, wherein the organic layer comprises a6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative of structuralformula I or a salt thereof:

wherein said organic layer does not substantially absorb incidentelectromagnetic radiation in the visible spectral range.
 24. Theanisotropic optical film of claim 23, wherein the organic layer is onthe front surface of a substrate, wherein the substrate comprises apolymer or glass.
 25. The anisotropic optical film of claim 23, whereinsaid organic layer is substantially insoluble in water or water-misciblesolvents.
 26. The anisotropic optical film of claim 23, wherein saidorganic layer contains two or more different6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives of structuralformula I.
 27. The anisotropic optical film of claim 23, wherein theorganic layer comprises a mixture of:2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-9-carboxylicacid, or a salt thereof; and2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-10-carboxylicacid, or a salt thereof.
 28. The anisotropic optical film of claim 23,wherein the film comprises two or more organic layers containingdifferent 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivatives ofstructural formula I, each capable of absorbing electromagneticradiation in at least one wavelength subrange of the UV spectral range.29. A method of producing an anisotropic optical film that does notsubstantially absorb incident electromagnetic radiation in the visiblespectral range, said method comprising: (a) depositing on a substrate anaqueous solution comprising a6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative of formula I ora salt thereof:

and (b) drying said aqueous solution so as to form a solid layer. 30.The method of claim 29, wherein the aqueous solution comprises:2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-9-carboxylicacid, or a salt thereof;2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-10-carboxylicacid, or a salt thereof; or a mixture of2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-9-carboxylicacid, or a salt thereof, and2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-10-carboxylicacid, or a salt thereof.
 31. The method of claim 29, wherein the aqueoussolution comprises a mixture of2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-9-carboxylicacid, or a salt thereof, and2(3)-sulfo-6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one-10-carboxylicacid, or a salt thereof.
 32. The method of claim 29, wherein saidaqueous solution is a lyotropic liquid crystal solution.
 33. The methodof claim 29, further comprising application of an external alignmentaction to the aqueous solution prior to the drying step.
 34. The methodof claim 29, wherein said aqueous solution comprises a water-misciblesolvent.
 35. The method of claim 29, wherein the substrate is treatedprior to the application of said aqueous solution so as to render itssurface hydrophilic.
 36. The method of claim 29, further comprisingtreatment of said formed solid layer with a solution of a water-solubleinorganic salt with Ba²⁺ cation.
 37. The method of claim 29, wherein thesequence of steps (a) and (b) are repeated two or more times and theaqueous solution used in the fabrication of each subsequent solid layeris either the same or different from that used in the previous cycle.